The present invention relates to the art of data entry units and more particularly to a portable data entry unit wherein the functional configuration of the unit may be readily selected in accordance with the needs of a particular end use.
In the daily operation of many businesses, data must be collected at a variety of locations and then transmitted to a central data collection point for tabulation and processing. Utility companies, for example, employ meter readers to collect the readings of utility meters at a large number of customer locations in order to determine the extent of utility usage by each customer in a given billing period. In applications involving other businesses, such as food stores, department stores, and other retail outlets, large amounts of data must be collected for inventory control purposes.
In order to simplify and improve the data collection process in these various businesses, portable electronic data collection devices have been developed and are currently in use. These devices permit an operator to electronically enter data into a bulk data storage (such as a magnetic tape or solid state memory) through a keyboard, scanning "wand", or other input device. The data, once collected, may then be electronically transmitted directly from the bulk data storage to a remote data collection location over ordinary telephone lines, either through the operation of the unit itself or through a peripheral device connected to it.
Although these data collection devices have found great utility in a large number of differing applications, problems have arisen in providing data collection devices which meet the varying needs of the diverse businesses which employ them. Thus, in each particular application it will be desirable to provide certain functions which, if not unique to that application, are at least common to only a relatively minor portion of the total market. Although it is possible to provide individual models which are uniquely designed for use in a particular application, these specially designed units will generally be more costly than similar, general purpose units enjoying a wider market. The individual users must therefore either settle for a general purpose unit which does not entirely meet his needs, or must bear the additional cost necessitated in the design of a unit specially prepared for that business. Clearly, neither alternative is very attractive.